Athletic flooring systems can be divided into two types; the floating type which rest upon resilient pads and is not attached to a base, and the fixed type which is anchored to the base and is usually supported by sleepers. With the floating type of system, the floor has desirable resiliency properties, but is capable of considerable horizontal displacement over time. With the fixed type of system the resilience of the floor is reduced but the floor is restrained from appreciable horizontal displacement.
In recent years a DIN system of rating athletic floors in point and area elasticity, ball rebound, and rolling load characteristics, to set standards of performance for athletic floors has been widely accepted in the flooring industry.
A detailed explanation of the testing that goes into the DIN certification process is found in a paper titled; Din 18032, Part 2, (March 1991); SPORTS HALLS; HALLS FOR GYMNASTICS AND SPORTS GAMES SPORTS SURFACES; REQUIREMENTS; TESTING, as translated from the German, by Hans J. Kolitzus 1ST/USSL April 1992.
Acquiring certification under the DIN 18032 Part 2 requirements involves a series of tests and measurements done by a certified tester, under specified conditions, using specified methods and equipment.
For each of the categories of tests a specified number of measurements are taken and the results computed and averaged. The average result for each category of test must then meet the requirements for DIN certification in that category.
Force Attenuation is a measure of the force reduction achieved by a test floor as a percent of the force reduction achieved by a standardized rigid floor (steel over cement on compacted earth). The DIN test involves a dropped test weight acting through a spring loaded force transfer instrument. The force reduction is computed as a percent as; (1-F.sub.max test /F.sub.max stand.).times.100. For certification that value must be a minimum of 58%.
Standard Deformation is a measure of the vertical displacement of a test floor in response the impact of a dropped weight, measured at the location of the dropped weight on the test floor. Standard deformation is measured in millimeters and is computed by a formula that contains correction factors. For DIN certification, the computed standard deformation must be between 3.0 mm. minimum, and 5.0 mm. maximum.
Deformation Trough is a measure of vertical displacement of a test floor at 500 mm. from the location of impact of a draped weight. Deformation trough is computed as a percentage of the displacement of the floor at the location of impact. A maximum percentage of 5% is permitted for DIN certification.
Rolling Load is a measure of the effects of a weighted test wheel which is rolled over defined strips on the test floor a prescribed number of times (300 passes). The test floor is then cut up and examined. For DIN certification, no damage to the floor or its substructure can be found and any remaining impressions must be less than 0.5 mm.
Ball Rebound is a measure of the rebound of a standardized basketball dropped from a set height on a test floor and is computed as a percentage of the rebound of the basketball from a rigid floor. For DIN certification, the percentage must be a minimum of 90%.
The DIN test contains other measures such as, Sliding Coefficient, which are concerned with properties other than those significantly influenced by the flooring system of this invention.
To date no fixed sleeper system known to the inventor has been found to be DIN certifiable.